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Two flavonoids, rutin and hesperidin, were investigated in vitro for anticoagulant activity through coagulation tests: activated partial thromboplastin time (aPTT), prothrombin time (PT) and thrombin time (TT). Only an ethanolic solution of rutin at the concentration of 830 µM prolonged aPTT, while TT and PT were unaffected. In order to evaluate whether the prolongation of aPTT was due to the decrease of coagulation factors, the experiment with deficient plasma was performed, showing the effects on factors VIII and IX. Since pharmacological activity of flavonoids is believed to increase when they are coordinated with metal ions, complexes of these flavonoids with Al(III) and Cu(II) ions were also tested. The results showed that complexes significantly prolonged aPTT and had no effects on PT and TT. Assay with deficient plasma (plasma having the investigated factor at less then 1%) revealed that complexes could bind to the coagulation factors, what may lead to a non-specific inhibition and aPTT prolongation. An effort was made to correlate stability of complexes with their anticoagulant properties.

In this study, we aimed at characterizing the structure and the anticoagulant activity of a polysaccharide fraction (AGP33) isolated from the gonads of Haliotis discus hannai Ino. AGP33 was extracted by enzymatic hydrolysis and purified by ion-exchange and gel-filtration chromatography. The backbone fraction of AGP33 (BAGP33), which appeared to contain of mannose, glucose and galactose, was prepared by partial acid hydrolysis. According to methylation and nuclear magnetic resonance (NMR) spectroscopy, the backbone of AGP33 was identified as mainly consisting of 1→3-linked, 1→4-linked, and 1→6-linked monosaccharides. AGP33 is a sulfated polysaccharide with sulfates occur at 3-O- and 4-O-positions. It prolonged thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) compared to a saline control solution in a dosage-dependent manner. AGP33 exhibited an extension (p < 0.01) of APTT compared to the saline group at concentrations higher than 5 μg/mL. AGP33 exhibited higher anticoagulant activity than its desulfated product (AGP33-des) and BAGP33. The results showed that polysaccharide with higher molecular weight and sulfate content demonstrated greater anticoagulant activity. [ABSTRACT FROM AUTHOR]

Two flavonoids, rutin and hesperidin, were investigated in vitro for anticoagulant activity through coagulation tests: activated partial thromboplastin time (aPTT), prothrombin time (PT) and thrombin time (TT). Only an ethanolic solution of rutin at the concentration of 830 μM prolonged aPTT, while TT and PT were unaffected. In order to evaluate whether the prolongation of aPTT was due to the decrease of coagulation factors, the experiment with deficient plasma was performed, showing the effects on factors VIII and IX. Since pharmacological activity of flavonoids is believed to increase when they are coordinated with metal ions, complexes of these flavonoids with Al(III) and Cu(II) ions were also tested. The results showed that complexes significantly prolonged aPTT and had no effects on PT and TT. Assay with deficient plasma (plasma having the investigated factor at less then 1%) revealed that complexes could bind to the coagulation factors, what may lead to a non-specific inhibition and aPTT prolongation. An effort was made to correlate stability of complexes with their anticoagulant properties. [ABSTRACT FROM AUTHOR]